Armed Forces Day celebrations take place across UK

Hundreds of veterans, serving personnel and cadets joined the Princess Royal and the prime minister for a day of military demonstrations in Stirling, which led the events.

A huge parade of services personnel - young and old - kicked off the proceedings, marching from Stirling Castle to the event grounds nearby.

A Red Arrows display was among a packed timetable of entertainment.

On the scene

By Caroline WyattDefence correspondent, BBC News

The parade began at Stirling Castle under stormy skies, at a place much fought over by the English and the Scots in the late Middle Ages.

That echo of battles past and battles still to come hung in the air as Prime Minister David Cameron stood near Alex Salmond, Scotland's first minister, as Her Royal Highness the Princess Royal took the salute.

Mr Salmond is the man hoping to lead the country to independence this September - in a referendum that's not the only one proving troublesome for Mr Cameron.

During the march past, an Indian-born veteran of the Parachute Regiment, Sergeant Milton Reilly, took the chance to tell Mr Salmond, the Princess Royal and the Prime Minister in person what he thought of the referendum, and his hopes that the UK would remain united, before he was moved along gently by security.

But most here wanted to keep politics out of a day that they say is here to remind the UK of the sacrifices of the UK's armed forces in the past and the present, rather than debate the future.

This afternoon, the Red Arrows will fly overhead - as well as the Battle of Britain memorial flight display, and the Royal Navy Historic flight.

All this, an unspoken reminder that the future of defence in Scotland - from its historic regiments to the nuclear deterrent base in Faslane - is also at stake when Scotland votes in September.

Representatives of the Army, Navy and Air Force took part in the event, the centrepiece of celebrations going on all over the country and at British military outposts abroad.

The day was also marked at Wimbledon, where services personnel were honoured on Centre Court.

Prime Minister David Cameron and Scotland's First Minister Alex Salmond were both on hand as Princess Anne took the salute from a group of veterans leading the 1,000-strong parade from Stirling Castle at 11:30 BST.

They headed through the Old Town and were joined by cadets and serving personnel at the Albert Halls, before making their way to the Royal Parklands.

Tanks and military vehicles were on display throughout the day, with demonstrations by Sea King and Apache helicopters.

Plane enthusiasts were treated to seeing the Lancaster and Spitfire in flight, along with more modern Typhoon and Tornado jets. A demonstration by the Red Arrows stunt team closed the event.

Other displays included Royal Marines fast-roping from helicopters, pipe bands, a parachute display by the Army's Red Devils, an artillery gun salute and troops staging a ground assault complete with casualty evacuations.

Meanwhile, the Queen attended a service honouring volunteers who served in World War One, 100 years on from the assassination of Archduke Franz Ferdinand in Sarajevo which led to the outbreak of war.

A display by the elite Red Arrows closed the day's events

More than 1,000 veterans, cadets and serving personnel took part in the march in Stirling, which led celebrations

Princess Anne and the prime minister greeted service personnel in Stirling

An artillery gun salute was fired from Stirling Castle

The armed services were also honoured on Centre Court at Wimbledon

A message from the Queen to mark the event praised the men and women of the forces as "admirable examples of professionalism and courage".

Analysis

By James CookScotland Correspondent, BBC News

It has been a day for celebrating martial prowess, a reminder that the warriors of these islands have been fighting at home and abroad for centuries.

An accident of anniversaries means the centenary of the shots which sparked the First World War fell in the same week as the 700th anniversary of the Battle of Bannockburn.

Both events were marked in Scotland today with daring displays and colourful commemorations.

Under the gaze of royalty, the forces of the British state paraded through Stirling while just a few miles away swords clashed as the victory of a Scottish king over the English was re-enacted.

But political hostilities were effectively suspended for a little while as Prime Minister David Cameron and First Minister Alex Salmond sang hymns together in the sunshine.

It didn't last.

Campaigners for the Union insist a vote for independence in September would throw the armed forces into turmoil, diminish the UK's standing in the world and put thousands of defence jobs at risk.

Their opponents say Scotland would actually be better defended as an independent nation, not least because it would stop spending billions on nuclear weapons and would refrain from fighting "illegal wars".

This battle is nearing its climax.

She added: "Then as now, they perform their duties in often the most difficult and dangerous of circumstances, both at home and overseas."

Politicians were united in voicing their support for the armed services, with rivals Mr Cameron, Ed Miliband and Mr Salmond all present in Stirling.

Mr Cameron said: "A lot of people want to show their respect for the armed forces, what they do, the values they bring to the country and also to say thank you to their families."

In a message on Twitter, Mr Miliband added: "Today we recognise the huge contribution the men and women of our armed forces have made to Britain. Thank you."

Mr Salmond said the events signified the respect for serving soldiers, veterans and military families and their "selfless service to preserve our democratic freedoms".

Air Chief Marshal Sir Stuart Peach, vice chief of the defence staff, said the event was a "very special opportunity" for the services to "unite with the society that we serve".

Organisers estimate the Armed Forces Day event will earn about £1m for the local economy, while boosting Stirling's reputation as a tourist destination.

Armed Forces Day is part of Stirling's "Big Weekend", which includes the Bannockburn Live battle re-enactment weekend, the Pipefest pipe band competition, and a night of open-air performances, entertainment and street art at Stirling's Big Night Out.

Thousands of spectators flocked to Stirling to see explosive military displays

Prime Minister David Cameron was in attendance at the opening parade

First Minister Alex Salmond and Labour party leader Ed Miliband were also in Stirling